Conventionally, as disclosed in, for example, Japanese Patent No. 5869459 (hereinafter referred to as “459”), a vehicle having a dual clutch type transmission gear mechanism as a multi-speed transmission mechanism is known. In a vehicle of ‘459’, an engine (a so-called vertical engine) is mounted so that the axis of the crankshaft is disposed along the longitudinal direction of the vehicle. This engine and a transmission case housing a dual clutch type transmission gear mechanism are combined to form a power unit, which is disposed at the front and rear center of the machine body.
A front transaxle having a differential mechanism for driving the front wheels is disposed in front of the power unit and a rear transaxle having a differential mechanism for driving the rear wheels is disposed behind the power unit Has been done. The output shaft of the multi-speed transmission mechanism of the power unit extends in the front and rear direction and between the front end of the output shaft and the front transaxle and between the rear end of the output shaft and the rear transaxle, Each of the front and rear wheels is driven by interposing a transmission shaft with a universal joint and distributing the output of the dual clutch transmission gear mechanism to the front and rear transaxle units.
The dual clutch multistage transmission gear mechanism applied to the power unit described above corresponds to a vertically mounted engine and has an axial core extending in the longitudinal direction of the vehicle as a gear shaft and a clutch shaft (this state is hereinafter referred to as “longitudinal extension Shaped” transmission shafts) are arranged side by side.
In response to such a vertically mounted engine, a multi-speed transmission mechanism comprising a dual clutch transmission gear mechanism having a plurality of longitudinally stretched gear shafts and clutch shafts arranged side by side is used as the left and right differential yoke shafts for driving the wheels There is an industrial demand to construct a transaxle as one unit in combination with a supported differential mechanism and a speed-reduction mechanism for transmitting power from the multi-speed transmission mechanism to the differential mechanism.
When configuring such a transaxle, the gear shaft and the clutch shaft constituting the multi-speed transmission mechanism are in the longitudinal (front-rear) direction, while the differential yoke shaft of the differential mechanism has an axis extending in the lateral (left-right) direction of the vehicle (Hereinafter, this state is referred to as “laterally extended”), and when a differential mechanism and a multi-speed transmission mechanism are combined, it is interposed between the output section of the multi-speed transmission mechanism and the input section of the differential mechanism It is desired that the structure of the differential mechanism becomes complicated and the entire transaxle is compact.